Exponential growth in Internet traffic has led to the need to scale networks far beyond present speed, capacity and performance. Optical fiber has the ability to transmit large amounts of data at high speeds with little need for retransmitting signals periodically over long distances. A further dramatic increase in the information capacity of an optical fiber can be achieved by the simultaneous transmission of optical signals over the same fiber from many different light sources having properly spaced peak emission wavelengths. By operating each source at a different peak wavelength, the integrity of the independent messages from each source is maintained for subsequent conversion to electric signals at the receiving end. This is the basis of wavelength division multiplexing (WDM). Wavelength division multiplexed fiber transmission and switching are seen as potential solutions to the performance and scaling bottlenecks in Internet Protocol (IP) networks and offer the potential for limited transparency to packet data-rate and format.
However, IP routing and forwarding presents a potential bottleneck as individual fiber link rates approach trillions of bits per second (Tbps). Although the speed at which data can be transmitted through fiber is extremely fast, most networks are still switched electronically, which greatly slows transmission speeds. There is little use for optical fiber in networks without optical switching and routing techniques to support such high data speeds. Therefore, optical packet switching technologies are necessary to deliver routing at terabit rates.